The three most commonly used networks in the world are The Internet, the Mobile Network and the Fixed Telephony Network and since these networks are essentially linked by a variety of gateways, they form the largest single ‘machine’ on the planet. Subscribers roam on these networks and connect at a variety of points using credentials. These credentials are either stored in Smartcards such as SIMs, on the devices themselves or in the subscribers' head as ‘passwords’. When a subscriber moves to a new portion of the network they must first identify themselves to that network and then gain access to that network using an authentication mechanism.
Patent Tagg WO 02/057869 described a method for users to connect to different portions of the Internet through a form of co-operative networking. This invention relates to a network mediated method for connecting to predominantly Mobile Networks.
In the GSM (Global System for Mobile communication) authentication is performed using a SIM inserted into the mobile communications device. This manages the connection to the network and contains the network subscriber keys. There are two types of authentication —home authentication and roaming authentication. Home authentication is straightforward and simply requires the exchange of a key with the home network to prove the subscribed user's identity. When the subscribed user is connected to the home network it is relatively straightforward to obtain the key, check it against the central database and then grant the subscribed user access to that network while keeping track of their usage for billing or credit management purposes. Typically, customers register to a network in a home location such as a country, state or region. This home location holds the primary record of that customer (subscribed user) and maintains the billing relationship with them. The home location usually maintains a record of the person's actual identity to allow for law enforcement activities, post pay billing and the like. In the case where the communications device is connected to a foreign network this process is more complex and is referred to as roaming.
‘Roaming’ refers to extending the connectivity of a service to a location that is different from a home location. When a mobile communications device, such as a mobile telephone, travels with a user outside of their home operator coverage area—‘territory’—the device can still access services using roaming mechanisms/services. However, there are a growing number of people who live in more than one home and, of course, machines such as airplanes and cars don't have a ‘home’ in the human sense of the word.
There are a growing number of internationally mobile people who spend significant time in more than one country. The International Air Transport Association (IATA) projects that by 2011 global airlines will be handling 2.75 billion passengers per year (up by 620 million from 2006). As a result of the number of internationally mobile people, it is expected that the number of people relying on mobile phones and similar mobile communications devices will increase accordingly. Informa Telecoms & Media statistics show international roaming significantly increasing, with European outbound roamers expected to increase from 131 m to 520 m (+397%) by 2010. Additionally significant growth is occurring in machine to machine communication where a SIM may be used for tracking consignments and merchantable goods and assets.
Users are poorly served by current systems, which were designed before the surge in international travel and are designed to handle customers who typically lived in one home and who very infrequently travelled away from that home. Users of cellular radio telephone services are familiar with the roaming surcharges levied for usage of a terminal device, typically a mobile phone, in a foreign network. In this sense a foreign network simply means a network other than the home network that the user originally subscribed to. Even the name ‘roaming surcharge’ belies the original network design which was for exceptional behaviour. However, roaming is now extremely common.
There are few options available to users when travelling to a foreign country which help reduce these surcharges:—
One option for a user is to purchase a plurality of additional pre-pay subscriber identification modules (SIMs), one for each territory which the user visits. A SIM is a plastic card with embedded electronic circuitry, which has a unique serial number and a unique international number for the mobile user (IMSI). The SIM enables communication between the mobile device and available cellular networks. Therefore, by purchasing a plurality of different SIMs,—one for each territory—the user is able to replace the original SIM with an appropriate SIM for the territory being visited. In this way, the mobile device appears to be a subscriber on the foreign network, which means the user can make and receive calls or use data services without incurring roaming surcharges.
This option has many disadvantages:                the user must purchase and carry around a plurality of different SIM cards;        the user must ensure that there is sufficient credit in the accounts linked with each SIM card. Furthermore, it is not desirable to have unused credit on a number of different networks, as this credit may be wasted without being redeemed;        The act of maintaining a plurality of different SIM accounts is cumbersome and time consuming, involving considerable user interaction;        When the Subscriber swaps SIM their mobile number changes this means they are no longer reachable on their normally used number. Further if they make an outbound call their Caller Line Identifier (CLI) will be a new one and therefore unknown to the receiver. This may result in the called party refusing to answer that call as the do not recognise the caller.        Law enforcement agencies are frustrated in their endeavours to keep track of undesirable people as they effectively have to keep track of multiple copies of the same person.        
Another option to reduce roaming charges is to use a service, such as the one described in Brunnekreef WO2006002951, where the user (or an application) on the mobile phone can pre-pend a (sometimes hidden) telephone number of an intermediate service that will accept the user's call, remove the pre-pended information and call the desired destination number. The caller then drops the call automatically and awaits a call-back. The intermediate service calls the user back to complete the connection, and this may give the user better calling rates than normal roaming surcharges. This has the disadvantage of introducing a delay in the communication channel while the user is trying to contact another party. Furthermore, the user gets a very poor user experience due to handset software compatibility issues: depending on the model of the mobile phone, the phone may appear to ‘do nothing’ until it gets the call back, strange messages such as ‘call failed’ or ‘call blocked’ may appear or the service may not work at all.
Multi-IMSI SIMs are available that offer the capability of being pre-programmed with a plurality of mobile subscriber data sets. The data sets are sometimes incorrectly referred to as IMSIs, hence the name ‘multi-IMSI SIM’, but are actually data sets which each comprise an international mobile subscriber identity (IMSI) and other network-related data.
These SIMS have processing capability and an algorithm to present the correct set of data to the phone based on the location of that phone. This allows the phone to present as a ‘local’ subscriber to the network in question. The problems associated with this algorithmic system include:                When a SIM is pre-programmed with fixed set of IMSIs, new SIMs need to be issued if additional IMSIs become available (likewise for deletion). Therefore, the physical management of the SIMs is very complex.        SIMs contain a preference table which list networks for which a suitable IMSI is available. These lists of preferences can change over time and the SIM will rapidly become out-of-date with respect to the reality of the network. This could result in roaming charges which are less favourable for the user.        While this option may provide a means to originate mobile calls at a local rate each network is independent of the other and the subscriber effectively becomes a different person on each network. In order for the subscriber to remain in contact with people from their home network the subscriber must either (i) forward calls from their home country telephone service to their current visited country's telephone service, (ii) inform their expected callers of their new number, or (iii) frequently check voicemail and missed calls in order to communicate with callers. This again is cumbersome and time consuming for the user.        
Many fixed format Dual and Multiple IMSI SIM systems have been sold by companies such a as VeriSign™, Gemalto™ and these are described in various patent applications such as Cammileri (WO2007102003), Stadelmann (WO9955107), Salomon (WO0221872), Bongers (WO0049820). In such systems, a piece of software runs in the SIM or on the handset or a separate electronic module and makes decisions as to which IMSI to use given the location and available networks. Such systems are sometimes called SmartSIMs, but in fact this is a misnomer as all SIMs are smart and contain a microprocessor and memory to run network selection and authentication programs. In addition to the physical problems of SIM management described above, there is a range of more subtle operational problems inherent in using a SIM algorithm and a table of IMSIs to effect a roaming solution:                One problem is that the algorithm must run in conjunction with information obtained from the handset and although theoretically all handsets conform with certain operating standards, in practice the implementation of such algorithms are highly incompatible. Therefore, SIM algorithm systems often fail to operate correctly in common handset models. These failures include:                    Random crashes;            Simple failure to perform the function; and            User messages that appear to make no sense.                        In addition, the SIM algorithm often has a lack of information about the network in which it runs and this can cause it to continuously hunt for an optimum network. During this time the handset may not reliably make and receive calls and the handset runs at full power, which can rapidly drain the battery.        If the algorithm pre-pends an access number this access number cannot be practically modified on a call by call basis and so call routing will not be optimized.        The SIM does not have enough knowledge of the network geography and current commercial status to choose the best network.        Such SIMs are essentially a fire and forget system. If the SIM locks onto the wrong network due to either a change in the network or a bug in the SIM, it may be lost for ever to the home network.        If the SIM connects to a network for which pre-pay control is not available then the SIM may be locked into a state where unlimited charges are permitted.        IMSI swapping to a foreign network renders the users normal value added services inoperable as the home network is now blind to the user. Services such as short codes, top-up numbers, voicemail and other convenience services no longer work in the expected way.        
Another problem travellers experience as they travel near country or region borders is that mobile phones may inadvertently attach to a foreign network, even though they may be physically in a home territory. Under normal operation, once a handset (i.e. a mobile phone) is attached to a network, it remains attached to it until signal is lost or if the subscriber manually disconnects. As a result, the user is charged high roaming charges for an extended period even if though they were physically in their home territory. In some regions such as Canada, USA and India where there is national roaming this effect can lead to accidentally high bills even when the customer is not travelling at all.